scripts/bb_mkdep.c

/*
 * Another fast dependencies generator for Makefiles, Version 4.0
 *
 * Copyright (C) 2005,2006 by Vladimir Oleynik <dzo@simtreas.ru>
 *
 * mmaping file may be originally by Linus Torvalds.
 *
 * infix parser/evaluator for #if expression
 *      Copyright (c) 2001 Aaron Lehmann <aaronl@vitelus.com>
 *      Copyright (c) 2001 Manuel Novoa III <mjn3@codepoet.org>
 *      Copyright (c) 2003 Vladimir Oleynik <dzo@simtreas.ru>
 *
 * bb_simplify_path()
 *      Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
 *
 * xmalloc() bb_xstrdup() bb_error_d():
 *      Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * llist routine
 *      Copyright (C) 2003 Glenn McGrath
 *      Copyright (C) Vladimir Oleynik <dzo@simtreas.ru>
 *
 * (c) 2005,2006 Bernhard Fischer:
 *  - commentary typos,
 *  - move "memory exhausted" into msg_enomem,
 *  - more verbose --help output.
 *
 * This program does:
 * 1) find #define KEY VALUE or #undef KEY from include/config.h
 * 2) recursive find and scan *.[ch] files, but skips scan of include/config/
 * 3) find #include "*.h" and KEYs using, if not as #define and #undef
 * 4) generate dependencies to stdout
 *    pwd/file.o: include/config/key*.h found_include_*.h
 *    path/inc.h: include/config/key*.h found_included_include_*.h
 * 5) save include/config/key*.h if changed after previous usage
 * This program does not generate dependencies for #include <...>
 * Config file can have #if #elif #else #ifdef #ifndef #endif lines
 */

#define LOCAL_INCLUDE_PATH          "include"
#define INCLUDE_CONFIG_PATH         LOCAL_INCLUDE_PATH"/config"
#define INCLUDE_CONFIG_KEYS_PATH    LOCAL_INCLUDE_PATH"/config.h"

#define bb_mkdep_full_options \
"\nOptions:" \
"\n\t-I local_include_path  include paths, default: \"" LOCAL_INCLUDE_PATH "\"" \
"\n\t-d                     don't generate depend" \
"\n\t-w                     show warning if include files not found" \
"\n\t-k include/config      default: \"" INCLUDE_CONFIG_PATH "\"" \
"\n\t-c include/config.h    configs, default: \"" INCLUDE_CONFIG_KEYS_PATH "\"" \
"\n\tdirs_to_scan           default \".\""

#define bb_mkdep_terse_options "Usage: [-I local_include_paths] [-dw] " \
		   "[-k path_for_stored_keys] [dirs]"


#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <getopt.h>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>


/* partial and simplified libbb routine */
static void bb_error_d(const char *s, ...) __attribute__ ((noreturn, format (printf, 1, 2)));
static char * bb_asprint(const char *format, ...) __attribute__ ((format (printf, 1, 2)));
static char *bb_simplify_path(const char *path);

/* stolen from libbb as is */
typedef struct llist_s {
	char *data;
	struct llist_s *link;
} llist_t;

static const char msg_enomem[] = "memory exhausted";

/* inline realization for fast works */
static inline void *xmalloc(size_t size)
{
	void *p = malloc(size);

	if(p == NULL)
		bb_error_d(msg_enomem);
	return p;
}

static inline char *bb_xstrdup(const char *s)
{
	char *r = strdup(s);

	if(r == NULL)
	    bb_error_d(msg_enomem);
	return r;
}


static int dontgenerate_dep;    /* flag -d usaged */
static int noiwarning;          /* flag -w usaged */
static llist_t *configs;    /* list of -c usaged and them stat() after parsed */
static llist_t *Iop;        /* list of -I include usaged */

static char *pwd;           /* current work directory */
static size_t replace;      /* replace current work directory with build dir */

static const char *kp;      /* KEY path, argument of -k used */
static size_t kp_len;
static struct stat st_kp;   /* stat(kp) */

typedef struct BB_KEYS {
	char *keyname;
	size_t key_sz;
	const char *value;
	const char *checked;
	char *stored_path;
	const char *src_have_this_key;
	struct BB_KEYS *next;
} bb_key_t;

static bb_key_t *key_top;   /* list of found KEYs */
static bb_key_t *Ifound;    /* list of parsed includes */


static void parse_conf_opt(const char *opt, const char *val, size_t key_sz);
static void parse_inc(const char *include, const char *fname);

static inline bb_key_t *check_key(bb_key_t *k, const char *nk, size_t key_sz)
{
    bb_key_t *cur;

    for(cur = k; cur; cur = cur->next) {
	if(key_sz == cur->key_sz && memcmp(cur->keyname, nk, key_sz) == 0) {
	    cur->checked = cur->stored_path;
	    return cur;
	}
    }
    return NULL;
}

static inline const char *lookup_key(const char *nk, size_t key_sz)
{
    bb_key_t *cur;

    for(cur = key_top; cur; cur = cur->next) {
	if(key_sz == cur->key_sz && memcmp(cur->keyname, nk, key_sz) == 0) {
	    return cur->value;
	}
    }
    return NULL;
}

/* for lexical analyser */
static int pagesizem1;      /* padding mask = getpagesize() - 1 */

/* for speed tricks */
static char first_chars[1+UCHAR_MAX];               /* + L_EOF */
static char isalnums[1+UCHAR_MAX];                  /* + L_EOF */

/* trick for fast find "define", "include", "undef",
"if((n)def)" "else", "endif"  */
static const char * const preproc[] = {
/* 0   1       2      3       4     5       6        7         8      9 */
"", "efine", "lif", "lse", "ndif", "f", "fdef", "fndef", "nclude", "ndef" };
static const unsigned char first_chars_deiu[UCHAR_MAX] = {
	[(int)'d'] = (unsigned char)(1|0x10),     /* define */
	[(int)'e'] = (unsigned char)(2|0x40),     /* elif, else, endif  */
	[(int)'i'] = (unsigned char)(5|0x80),     /* if ifdef ifndef include */
	[(int)'u'] = (unsigned char)(9|0x90),     /* undef */
};

#define CONFIG_MODE  0
#define IF0_MODE     1  /* #if 0  */
#define IF1_MODE     2  /* #if 1 */
#define ELSE0_MODE   4  /* #else found after #if 0 */
#define ELSE1_MODE   8  /* #else found after #if 1 */
#define ELIF1_MODE   16 /* #elif found after #if 1 */
#define FALSE_MODES  (IF0_MODE|ELSE1_MODE|ELIF1_MODE)

#define yy_error_d(s) bb_error_d("%s:%d hmm, %s", fname, line, s)

/* state */
#define S      0        /* start state */
#define STR    '"'      /* string */
#define CHR    '\''     /* char */
#define REM    '/'      /* block comment */
#define BS     '\\'     /* back slash */
#define POUND  '#'      /* # */
#define D      '1'      /* #define preprocessor's directive */
#define EI     '2'      /* #elif preprocessor's directive */
#define E      '3'      /* #else preprocessor's directive */
#define EF     '4'      /* #endif preprocessor's directive */
#define F      '5'      /* #if preprocessor's directive */
#define IFD    '6'      /* #ifdef preprocessor's directive */
#define IFND   '7'      /* #ifndef preprocessor's directive */
#define I      '8'      /* #include preprocessor's directive */
#define U      '9'      /* #undef preprocessor's directive */
#define DK     'K'      /* #define KEY... (config mode) */
#define ANY    '*'      /* any unparsed chars */

/* [A-Z_a-z] */
#define ID(c) ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
/* [A-Z_a-z0-9] */
#define ISALNUM(c)  (ID(c) || (c >= '0' && c <= '9'))

#define L_EOF  (1+UCHAR_MAX)

#define getc0()     do { c = (optr >= oend) ? L_EOF : *optr++; } while(0)

#define getc1()     do { getc0(); if(c == BS) { getc0(); \
				    if(c == '\n') { line++; continue; } \
				    else { optr--; c = BS; } \
				  } break; } while(1)

static char id_s[4096];
#define put_id(ic)  do {    if(id_len == sizeof(id_s)) goto too_long; \
				id[id_len++] = ic; } while(0)

static char ifcpp_stack[1024];
static int  ptr_ifcpp_stack;
#define push_mode() do { \
			if(ptr_ifcpp_stack == (int)sizeof(ifcpp_stack)) \
				yy_error_d("#if* stack overflow"); \
			ifcpp_stack[ptr_ifcpp_stack++] = (char)mode; \
			} while(0)

#define pop_mode()  do { \
			if(ptr_ifcpp_stack == 0) \
				yy_error_d("unexpected #endif"); \
			mode = ifcpp_stack[--ptr_ifcpp_stack]; \
			} while(0)

/* #if expression */
typedef long long arith_t;

static arith_t arith (const char *expr, int *perrcode);

/* The code uses a simple two-stack algorithm. See
 * http://www.onthenet.com.au/~grahamis/int2008/week02/lect02.html
 * for a detailed explanation of the infix-to-postfix algorithm on which
 * this is based (this code differs in that it applies operators immediately
 * to the stack instead of adding them to a queue to end up with an
 * expression). */

#define arith_isspace(arithval) \
	(arithval == ' ' || arithval == '\v' || arithval == '\t' || arithval == '\f')


typedef unsigned char operator;

/* An operator's token id is a bit of a bitfield. The lower 5 bits are the
 * precedence, and 3 high bits are an ID unique across operators of that
 * precedence. The ID portion is so that multiple operators can have the
 * same precedence, ensuring that the leftmost one is evaluated first.
 * Consider * and /. */

#define tok_decl(prec,id) (((id)<<5)|(prec))
#define PREC(op) ((op) & 0x1F)

#define TOK_LPAREN tok_decl(0,0)

#define TOK_COMMA tok_decl(1,0)

/* conditional is right associativity too */
#define TOK_CONDITIONAL tok_decl(2,0)
#define TOK_CONDITIONAL_SEP tok_decl(2,1)

#define TOK_OR tok_decl(3,0)

#define TOK_AND tok_decl(4,0)

#define TOK_BOR tok_decl(5,0)

#define TOK_BXOR tok_decl(6,0)

#define TOK_BAND tok_decl(7,0)

#define TOK_EQ tok_decl(8,0)
#define TOK_NE tok_decl(8,1)

#define TOK_LT tok_decl(9,0)
#define TOK_GT tok_decl(9,1)
#define TOK_GE tok_decl(9,2)
#define TOK_LE tok_decl(9,3)

#define TOK_LSHIFT tok_decl(10,0)
#define TOK_RSHIFT tok_decl(10,1)

#define TOK_ADD tok_decl(11,0)
#define TOK_SUB tok_decl(11,1)

#define TOK_MUL tok_decl(12,0)
#define TOK_DIV tok_decl(12,1)
#define TOK_REM tok_decl(12,2)

/* For now unary operators. */
#define UNARYPREC 13
#define TOK_BNOT tok_decl(UNARYPREC,0)
#define TOK_NOT tok_decl(UNARYPREC,1)

#define TOK_UMINUS tok_decl(UNARYPREC+1,0)
#define TOK_UPLUS tok_decl(UNARYPREC+1,1)

#define SPEC_PREC (UNARYPREC+1)

#define TOK_NUM tok_decl(SPEC_PREC, 0)
#define TOK_RPAREN tok_decl(SPEC_PREC, 1)

#define NUMPTR (*numstackptr)

typedef struct ARITCH_VAR_NUM {
	arith_t val;
	arith_t contidional_second_val;
	char contidional_second_val_initialized;
} v_n_t;


typedef struct CHK_VAR_RECURSIVE_LOOPED {
	const char *var;
	size_t var_sz;
	struct CHK_VAR_RECURSIVE_LOOPED *next;
} chk_var_recursive_looped_t;

static chk_var_recursive_looped_t *prev_chk_var_recursive;


static int arith_lookup_val(const char *var, size_t key_sz, arith_t *pval)
{
    const char * p = lookup_key(var, key_sz);

    if(p) {
	int errcode;

	/* recursive try as expression */
	chk_var_recursive_looped_t *cur;
	chk_var_recursive_looped_t cur_save;

	for(cur = prev_chk_var_recursive; cur; cur = cur->next) {
	    if(cur->var_sz == key_sz && memcmp(cur->var, var, key_sz) == 0) {
		/* expression recursion loop detected */
		return -5;
	    }
	}
	/* save current lookuped var name */
	cur = prev_chk_var_recursive;
	cur_save.var = var;
	cur_save.var_sz = key_sz;
	cur_save.next = cur;
	prev_chk_var_recursive = &cur_save;

	*pval = arith (p, &errcode);
	/* restore previous ptr after recursiving */
	prev_chk_var_recursive = cur;
	return errcode;
    } else {
	/* disallow undefined var */
	fprintf(stderr, "%.*s ", (int)key_sz, var);
	return -4;
    }
}

/* "applying" a token means performing it on the top elements on the integer
 * stack. For a unary operator it will only change the top element, but a
 * binary operator will pop two arguments and push a result */
static inline int
arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
{
	v_n_t *numptr_m1;
	arith_t numptr_val, rez;

	if (NUMPTR == numstack) goto err; /* There is no operator that can work
										 without arguments */
	numptr_m1 = NUMPTR - 1;

	rez = numptr_m1->val;
	if (op == TOK_UMINUS)
		rez *= -1;
	else if (op == TOK_NOT)
		rez = !rez;
	else if (op == TOK_BNOT)
		rez = ~rez;
	else if (op != TOK_UPLUS) {
		/* Binary operators */

	    /* check and binary operators need two arguments */
	    if (numptr_m1 == numstack) goto err;

	    /* ... and they pop one */
	    --NUMPTR;
	    numptr_val = rez;
	    if (op == TOK_CONDITIONAL) {
		if(! numptr_m1->contidional_second_val_initialized) {
		    /* protect $((expr1 ? expr2)) without ": expr" */
		    goto err;
		}
		rez = numptr_m1->contidional_second_val;
	    } else if(numptr_m1->contidional_second_val_initialized) {
		    /* protect $((expr1 : expr2)) without "expr ? " */
		    goto err;
	    }
	    numptr_m1 = NUMPTR - 1;
	    if (op == TOK_CONDITIONAL) {
		    numptr_m1->contidional_second_val = rez;
	    }
	    rez = numptr_m1->val;
	    if (op == TOK_BOR)
			rez |= numptr_val;
	    else if (op == TOK_OR)
			rez = numptr_val || rez;
	    else if (op == TOK_BAND)
			rez &= numptr_val;
	    else if (op == TOK_BXOR)
			rez ^= numptr_val;
	    else if (op == TOK_AND)
			rez = rez && numptr_val;
	    else if (op == TOK_EQ)
			rez = (rez == numptr_val);
	    else if (op == TOK_NE)
			rez = (rez != numptr_val);
	    else if (op == TOK_GE)
			rez = (rez >= numptr_val);
	    else if (op == TOK_RSHIFT)
			rez >>= numptr_val;
	    else if (op == TOK_LSHIFT)
			rez <<= numptr_val;
	    else if (op == TOK_GT)
			rez = (rez > numptr_val);
	    else if (op == TOK_LT)
			rez = (rez < numptr_val);
	    else if (op == TOK_LE)
			rez = (rez <= numptr_val);
	    else if (op == TOK_MUL)
			rez *= numptr_val;
	    else if (op == TOK_ADD)
			rez += numptr_val;
	    else if (op == TOK_SUB)
			rez -= numptr_val;
	    else if (op == TOK_COMMA)
			rez = numptr_val;
	    else if (op == TOK_CONDITIONAL_SEP) {
			if (numptr_m1 == numstack) {
			    /* protect $((expr : expr)) without "expr ? " */
			    goto err;
			}
			numptr_m1->contidional_second_val_initialized = op;
			numptr_m1->contidional_second_val = numptr_val;
	    }
	    else if (op == TOK_CONDITIONAL) {
			rez = rez ?
			      numptr_val : numptr_m1->contidional_second_val;
	    }
	    else if(numptr_val==0)          /* zero divisor check */
			return -2;
	    else if (op == TOK_DIV)
			rez /= numptr_val;
	    else if (op == TOK_REM)
			rez %= numptr_val;
	}
	numptr_m1->val = rez;
	return 0;
err: return(-1);
}

/* longest must first */
static const char op_tokens[] = {
	'<','<',    0, TOK_LSHIFT,
	'>','>',    0, TOK_RSHIFT,
	'|','|',    0, TOK_OR,
	'&','&',    0, TOK_AND,
	'!','=',    0, TOK_NE,
	'<','=',    0, TOK_LE,
	'>','=',    0, TOK_GE,
	'=','=',    0, TOK_EQ,
	'!',        0, TOK_NOT,
	'<',        0, TOK_LT,
	'>',        0, TOK_GT,
	'|',        0, TOK_BOR,
	'&',        0, TOK_BAND,
	'*',        0, TOK_MUL,
	'/',        0, TOK_DIV,
	'%',        0, TOK_REM,
	'+',        0, TOK_ADD,
	'-',        0, TOK_SUB,
	'^',        0, TOK_BXOR,
	'~',        0, TOK_BNOT,
	',',        0, TOK_COMMA,
	'?',        0, TOK_CONDITIONAL,
	':',        0, TOK_CONDITIONAL_SEP,
	')',        0, TOK_RPAREN,
	'(',        0, TOK_LPAREN,
	0
};
/* ptr to ")" */
#define endexpression &op_tokens[sizeof(op_tokens)-7]

/*
 * Return of a legal variable name (a letter or underscore followed by zero or
 * more letters, underscores, and digits).
 */

static inline char *
endofname(const char *name)
{
	char *p;

	p = (char *) name;
	if (! ID(*p))
		return p;
	while (*++p) {
		if (! ISALNUM(*p))
			break;
	}
	return p;
}


/* Like strncpy but make sure the resulting string is always 0 terminated. */
static inline char * safe_strncpy(char *dst, const char *src, size_t size)
{
	dst[size-1] = '\0';
	return strncpy(dst, src, size-1);
}

static arith_t arith (const char *expr, int *perrcode)
{
    char arithval;          /* Current character under analysis */
    operator lasttok, op;
    operator prec;

    const char *p = endexpression;
    int errcode;

    size_t datasizes = strlen(expr) + 2;

    /* Stack of integers */
    /* The proof that there can be no more than strlen(startbuf)/2+1 integers
     * in any given correct or incorrect expression is left as an exercise to
     * the reader. */
    v_n_t *numstack = alloca(((datasizes)/2)*sizeof(v_n_t)),
	    *numstackptr = numstack;
    /* Stack of operator tokens */
    operator *stack = alloca((datasizes) * sizeof(operator)),
	    *stackptr = stack;

    *stackptr++ = lasttok = TOK_LPAREN;     /* start off with a left paren */
    *perrcode = errcode = 0;

    while(1) {
	if ((arithval = *expr) == 0) {
		if (p == endexpression) {
			/* Null expression. */
err:
			return (*perrcode = -1);
		}

		/* This is only reached after all tokens have been extracted from the
		 * input stream. If there are still tokens on the operator stack, they
		 * are to be applied in order. At the end, there should be a final
		 * result on the integer stack */

		if (expr != endexpression + 1) {
			/* If we haven't done so already, */
			/* append a closing right paren */
			expr = endexpression;
			/* and let the loop process it. */
			continue;
		}
		/* At this point, we're done with the expression. */
		if (numstackptr != numstack+1) {
			/* ... but if there isn't, it's bad */
			goto err;
		}
	ret:
		*perrcode = errcode;
		return numstack->val;
	} else {
		/* Continue processing the expression. */
		if (arith_isspace(arithval)) {
			/* Skip whitespace */
			goto prologue;
		}
		if((p = endofname(expr)) != expr) {
			size_t var_name_size = (p-expr);

			if(var_name_size == 7 &&
				strncmp(expr, "defined", var_name_size) == 0) {
			    int brace_form = 0;
			    const char *v;

			    while(arith_isspace(*p)) p++;
			    if(*p == '(') {
				p++;
				while(arith_isspace(*p)) p++;
				brace_form = 1;
			    }
			    expr = p;
			    if((p = endofname(expr)) == expr)
				goto err;
			    var_name_size = (p-expr);
			    while(arith_isspace(*p)) p++;
			    if(brace_form && *p++ != ')')
				goto err;
			    v = lookup_key(expr, var_name_size);
			    numstackptr->val = (v != NULL) ? 1 : 0;
			} else {
			    errcode = arith_lookup_val(expr, var_name_size,
					&(numstackptr->val));
			    if(errcode) goto ret;
			}
			expr = p;
		num:
			numstackptr->contidional_second_val_initialized = 0;
			numstackptr++;
			lasttok = TOK_NUM;
			continue;
		} else if (arithval >= '0' && arithval <= '9') {
			numstackptr->val = strtoll(expr, (char **) &expr, 0);
			while(*expr == 'l' || *expr == 'L' || *expr == 'u' ||
								*expr == 'U')
			    expr++;
			goto num;
		}
		for(p = op_tokens; ; p++) {
			const char *o;

			if(*p == 0) {
				/* strange operator not found */
				goto err;
			}
			for(o = expr; *p && *o == *p; p++)
				o++;
			if(! *p) {
				/* found */
				expr = o - 1;
				break;
			}
			/* skip tail uncompared token */
			while(*p)
				p++;
			/* skip zero delim */
			p++;
		}
		op = p[1];

		/* Plus and minus are binary (not unary) _only_ if the last
		 * token was as number, or a right paren (which pretends to be
		 * a number, since it evaluates to one). Think about it.
		 * It makes sense. */
		if (lasttok != TOK_NUM) {
			if(op == TOK_ADD)
			    op = TOK_UPLUS;
			else if(op == TOK_SUB)
			    op = TOK_UMINUS;
		}
		/* We don't want a unary operator to cause recursive descent on the
		 * stack, because there can be many in a row and it could cause an
		 * operator to be evaluated before its argument is pushed onto the
		 * integer stack. */
		/* But for binary operators, "apply" everything on the operator
		 * stack until we find an operator with a lesser priority than the
		 * one we have just extracted. */
		/* Left paren is given the lowest priority so it will never be
		 * "applied" in this way.
		 * if associativity is right and priority eq, applied also skip
		 */
		prec = PREC(op);
		if ((prec > 0 && prec < UNARYPREC) || prec == SPEC_PREC) {
			/* not left paren or unary */
			if (lasttok != TOK_NUM) {
				/* binary op must be preceded by a num */
				goto err;
			}
			while (stackptr != stack) {
			    if (op == TOK_RPAREN) {
				/* The algorithm employed here is simple: while we don't
				 * hit an open paren nor the bottom of the stack, pop
				 * tokens and apply them */
				if (stackptr[-1] == TOK_LPAREN) {
				    --stackptr;
				    /* Any operator directly after a */
				    lasttok = TOK_NUM;
				    /* close paren should consider itself binary */
				    goto prologue;
				}
			    } else {
				operator prev_prec = PREC(stackptr[-1]);

				if (prev_prec < prec)
					break;
				/* check right assoc */
				if(prev_prec == prec && prec == PREC(TOK_CONDITIONAL))
					break;
			    }
			    errcode = arith_apply(*--stackptr, numstack, &numstackptr);
			    if(errcode) goto ret;
			}
			if (op == TOK_RPAREN) {
				goto err;
			}
		}

		/* Push this operator to the stack and remember it. */
		*stackptr++ = lasttok = op;

	  prologue:
		++expr;
	}
    }
}

/* stupid C lexical analyser for configs.h */
static void c_lex_config(const char *fname, long fsize)
{
  int c;
  int state;
  int line;
  char *id = id_s;
  size_t id_len = 0;                /* stupid initialization */
  unsigned char *optr, *oend;
  int mode = CONFIG_MODE;

  int fd;
  char *map;
  int mapsize;

  if(fsize == 0) {
    fprintf(stderr, "Warning: %s is empty\n", fname);
    return;
  }
  fd = open(fname, O_RDONLY);
  if(fd < 0) {
	perror(fname);
	return;
  }
  mapsize = (fsize+pagesizem1) & ~pagesizem1;
  map = mmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, fd, 0);
  if ((long) map == -1)
	bb_error_d("%s: mmap: %m", fname);

  optr = (unsigned char *)map;
  oend = optr + fsize;

  line = 1;
  state = S;

  for(;;) {
    getc1();
    for(;;) {
	/* [ \t]+ eat first space */
	while(c == ' ' || c == '\t')
	    getc1();

	if(state == S) {
		while(first_chars[c] == ANY) {
		    /* <S>unparsed */
		    if(c == '\n')
			line++;
		    getc1();
		}
		if(c == L_EOF) {
			/* <S><<EOF>> */
			munmap(map, mapsize);
			close(fd);
			if(mode != CONFIG_MODE)
				yy_error_d("expected #endif");
			return;
		}
		if(c == REM) {
			/* <S>/ */
			getc0();
			if(c == REM) {
				/* <S>"//"[^\n]* */
				do getc0(); while(c != '\n' && c != L_EOF);
			} else if(c == '*') {
				/* <S>[/][*] goto parse block comments */
				break;
			}
		} else if(c == POUND) {
			/* <S># */
			state = c;
			getc1();
		} else if(c == STR || c == CHR) {
			/* <S>\"|\' */
			int qc = c;

			for(;;) {
			    /* <STR,CHR>. */
			    getc1();
			    if(c == qc) {
				/* <STR>\" or <CHR>\' */
				break;
			    }
			    if(c == BS) {
				/* <STR,CHR>\\ but is not <STR,CHR>\\\n */
				getc0();
			    }
			    if(c == '\n' || c == L_EOF)
				yy_error_d("unterminated");
			}
			getc1();
		} else {
			/* <S>[A-Z_a-z0-9] */

			/* trick for fast drop id
			   if key with this first char undefined */
			if(first_chars[c] == 0 || (mode & FALSE_MODES) != 0) {
			    /* skip <S>[A-Z_a-z0-9]+ */
			    do getc1(); while(isalnums[c]);
			} else {
			    id_len = 0;
			    do {
				/* <S>[A-Z_a-z0-9]+ */
				put_id(c);
				getc1();
			    } while(isalnums[c]);
			    check_key(key_top, id, id_len);
			}
		}
		continue;
	}
	/* begin preprocessor states */
	if(c == L_EOF)
	    yy_error_d("unexpected EOF");
	if(c == REM) {
		/* <#.*>/ */
		getc0();
		if(c == REM)
			yy_error_d("detected // in preprocessor line");
		if(c == '*') {
			/* <#.*>[/][*] goto parse block comments */
			break;
		}
		/* hmm, #.*[/] */
		yy_error_d("strange preprocessor line");
	}
	if(state == POUND) {
	    /* tricks */
	    int diu = (int)first_chars_deiu[c];   /* preproc ptr */

	    state = S;
	    if(diu != S) {
		int p_num_str, p_num_max;

		getc1();
		id_len = 0;
		while(isalnums[c]) {
		    put_id(c);
		    getc1();
		}
		put_id(0);
		p_num_str = diu & 0xf;
		p_num_max = diu >> 4;
		for(diu = p_num_str; diu <= p_num_max; diu++)
		    if(!strcmp(id, preproc[diu])) {
			state = (diu + '0');
			/* common */
			id_len = 0;
			break;
		}
	    } else {
		while(isalnums[c]) getc1();
	    }
	} else if(state == EF) {
		/* #endif */
		pop_mode();
		state = S;
	} else if(state == I) {
		if(c == STR && (mode & FALSE_MODES) == 0) {
			/* <I>\" */
			for(;;) {
			    getc1();
			    if(c == STR)
				break;
			    if(c == L_EOF)
				yy_error_d("unexpected EOF");
			    put_id(c);
			}
			put_id(0);
			/* store "include.h" */
			parse_inc(id, fname);
			getc1();
		}
		/* else another (may be wrong) #include ... */
		state = S;
	} else if(state == F) {
	    arith_t t;
	    int errcode;

	    while(c != '\n' && c != L_EOF) {
		put_id(c);
		getc1();
	    }
	    put_id(0);
	    t = arith(id, &errcode);
	    if (errcode < 0) {
		if (errcode == -2)
		    yy_error_d("divide by zero");
		else if (errcode == -4)
		    yy_error_d("undefined");
		else if (errcode == -5)
		    yy_error_d("expression recursion loop detected");
		else
		    yy_error_d("syntax error");
	    }
	    push_mode();
	    mode = t != 0 ? IF1_MODE : IF0_MODE;
	    state = S;
	} else if(state == IFD || state == IFND) {
	    /* save KEY from #if(n)def KEY ... */
	    const char *v;

	    push_mode();
	    while(isalnums[c]) {
		put_id(c);
		getc1();
	    }
	    if(!id_len)
		yy_error_d("expected identifier");
	    v = lookup_key(id, id_len);
	    mode = IF1_MODE;
	    if(state == IFD && v == NULL)
		mode = IF0_MODE;
	    else if(state == IFND && v != NULL)
		    mode = IF0_MODE;
	    state = S;
	} else if(state == EI) {
	    /* #elif */
	    if(mode == CONFIG_MODE || mode == ELSE0_MODE || mode == ELSE1_MODE)
		yy_error_d("unexpected #elif");
	    if(mode == IF0_MODE) {
		pop_mode();
		state = F;
	    } else {
		mode = ELIF1_MODE;
		state = S;
	    }
	} else if(state == E) {
	    if(mode == CONFIG_MODE || mode == ELSE0_MODE || mode == ELSE1_MODE)
		yy_error_d("unexpected #else");
	    if(mode == IF0_MODE)
		mode = ELSE0_MODE;
	    else if(mode == IF1_MODE)
		mode = ELSE1_MODE;
	    state = S;
	} else if(state == D || state == U) {
	    /* save KEY from #"define"|"undef" ... */
	    while(isalnums[c]) {
		put_id(c);
		getc1();
	    }
	    if(!id_len)
		yy_error_d("expected identifier");
	    if(state == U) {
		if((mode & FALSE_MODES) == 0)
		    parse_conf_opt(id, NULL, id_len);
		state = S;
	    } else {
		/* D -> DK */
		state = DK;
	    }
	} else {
	    /* state==<DK> #define KEY[ ] */
	    size_t opt_len = id_len;
	    char *val = id + opt_len;
	    char *sp;

	    for(;;) {
		if(c == L_EOF || c == '\n')
		    break;
		put_id(c);
		getc1();
	    }
	    sp = id + id_len;
	    put_id(0);
	    /* trim tail spaces */
	    while(--sp >= val && (*sp == ' ' || *sp == '\t'
				|| *sp == '\f' || *sp == '\v'))
		*sp = '\0';
	    if((mode & FALSE_MODES) == 0)
		parse_conf_opt(id, val, opt_len);
	    state = S;
	}
    }

    /* <REM> */
    getc0();
    for(;;) {
	  /* <REM>[^*]+ */
	  while(c != '*') {
		if(c == '\n') {
		    /* <REM>\n */
		    if(state != S)
			yy_error_d("unexpected newline");
		    line++;
		} else if(c == L_EOF)
		    yy_error_d("unexpected EOF");
		getc0();
	  }
	  /* <REM>[*] */
	  getc0();
	  if(c == REM) {
		/* <REM>[*][/] */
		break;
	  }
    }
  }
too_long:
  yy_error_d("phrase too long");
}

/* trick for fast find "define", "include", "undef" */
static const char first_chars_diu[UCHAR_MAX] = {
	[(int)'d'] = (char)5,           /* strlen("define")  - 1; */
	[(int)'i'] = (char)6,           /* strlen("include") - 1; */
	[(int)'u'] = (char)4,           /* strlen("undef")   - 1; */
};

#undef D
#undef I
#undef U
#define D      '5'      /* #define preprocessor's directive */
#define I      '6'      /* #include preprocessor's directive */
#define U      '4'      /* #undef preprocessor's directive */

/* stupid C lexical analyser for sources */
static void c_lex_src(const char *fname, long fsize)
{
  int c;
  int state;
  int line;
  char *id = id_s;
  size_t id_len = 0;                /* stupid initialization */
  unsigned char *optr, *oend;

  int fd;
  char *map;
  int mapsize;

  if(fsize == 0) {
    fprintf(stderr, "Warning: %s is empty\n", fname);
    return;
  }
  fd = open(fname, O_RDONLY);
  if(fd < 0) {
	perror(fname);
	return;
  }
  mapsize = (fsize+pagesizem1) & ~pagesizem1;
  map = mmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, fd, 0);
  if ((long) map == -1)
	bb_error_d("%s: mmap: %m", fname);

  optr = (unsigned char *)map;
  oend = optr + fsize;

  line = 1;
  state = S;

  for(;;) {
    getc1();
    for(;;) {
	/* [ \t]+ eat first space */
	while(c == ' ' || c == '\t')
	    getc1();

	if(state == S) {
		while(first_chars[c] == ANY) {
		    /* <S>unparsed */
		    if(c == '\n')
			line++;
		    getc1();
		}
		if(c == L_EOF) {
			/* <S><<EOF>> */
			munmap(map, mapsize);
			close(fd);
			return;
		}
		if(c == REM) {
			/* <S>/ */
			getc0();
			if(c == REM) {
				/* <S>"//"[^\n]* */
				do getc0(); while(c != '\n' && c != L_EOF);
			} else if(c == '*') {
				/* <S>[/][*] goto parse block comments */
				break;
			}
		} else if(c == POUND) {
			/* <S># */
			state = c;
			getc1();
		} else if(c == STR || c == CHR) {
			/* <S>\"|\' */
			int qc = c;

			for(;;) {
			    /* <STR,CHR>. */
			    getc1();
			    if(c == qc) {
				/* <STR>\" or <CHR>\' */
				break;
			    }
			    if(c == BS) {
				/* <STR,CHR>\\ but is not <STR,CHR>\\\n */
				getc0();
			    }
			    if(c == '\n' || c == L_EOF)
				yy_error_d("unterminated");
			}
			getc1();
		} else {
			/* <S>[A-Z_a-z0-9] */

			/* trick for fast drop id
			   if key with this first char undefined */
			if(first_chars[c] == 0) {
			    /* skip <S>[A-Z_a-z0-9]+ */
			    do getc1(); while(isalnums[c]);
			} else {
			    id_len = 0;
			    do {
				/* <S>[A-Z_a-z0-9]+ */
				put_id(c);
				getc1();
			    } while(isalnums[c]);
			    check_key(key_top, id, id_len);
			}
		}
		continue;
	}
	/* begin preprocessor states */
	if(c == L_EOF)
	    yy_error_d("unexpected EOF");
	if(c == REM) {
		/* <#.*>/ */
		getc0();
		if(c == REM)
			yy_error_d("detected // in preprocessor line");
		if(c == '*') {
			/* <#.*>[/][*] goto parse block comments */
			break;
		}
		/* hmm, #.*[/] */
		yy_error_d("strange preprocessor line");
	}
	if(state == POUND) {
	    /* tricks */
	    static const char * const p_preproc[] = {
		    /* 0 1   2  3     4        5        6 */
		    "", "", "", "", "ndef", "efine", "nclude"
	    };
	    size_t diu = first_chars_diu[c];   /* strlen and p_preproc ptr */

	    state = S;
	    if(diu != S) {
		getc1();
		id_len = 0;
		while(isalnums[c]) {
		    put_id(c);
		    getc1();
		}
		/* str begins with c, read == strlen key and compared */
		if(diu == id_len && !memcmp(id, p_preproc[diu], diu)) {
		    state = diu + '0';
		    id_len = 0; /* common for save */
		}
	    } else {
		while(isalnums[c]) getc1();
	    }
	} else if(state == I) {
		if(c == STR) {
			/* <I>\" */
			for(;;) {
			    getc1();
			    if(c == STR)
				break;
			    if(c == L_EOF)
				yy_error_d("unexpected EOF");
			    put_id(c);
			}
			put_id(0);
			/* store "include.h" */
			parse_inc(id, fname);
			getc1();
		}
		/* else another (may be wrong) #include ... */
		state = S;
	} else /* if(state == D || state == U) */ {
		/* ignore depend with #define or #undef KEY */
		while(isalnums[c]) getc1();
		state = S;
	}
    }

    /* <REM> */
    getc0();
    for(;;) {
	  /* <REM>[^*]+ */
	  while(c != '*') {
		if(c == '\n') {
		    /* <REM>\n */
		    if(state != S)
			yy_error_d("unexpected newline");
		    line++;
		} else if(c == L_EOF)
		    yy_error_d("unexpected EOF");
		getc0();
	  }
	  /* <REM>[*] */
	  getc0();
	  if(c == REM) {
		/* <REM>[*][/] */
		break;
	  }
    }
  }
too_long:
  yy_error_d("phrase too long");
}


/* bb_simplify_path special variant for absolute pathname */
static size_t bb_qa_simplify_path(char *path)
{
	char *s, *p;

	p = s = path;

	do {
	    if (*p == '/') {
		if (*s == '/') {    /* skip duplicate (or initial) slash */
		    continue;
		} else if (*s == '.') {
		    if (s[1] == '/' || s[1] == 0) { /* remove extra '.' */
			continue;
		    } else if ((s[1] == '.') && (s[2] == '/' || s[2] == 0)) {
			++s;
			if (p > path) {
			    while (*--p != '/');    /* omit previous dir */
			}
			continue;
		    }
		}
	    }
	    *++p = *s;
	} while (*++s);

	if ((p == path) || (*p != '/')) {  /* not a trailing slash */
	    ++p;                            /* so keep last character */
	}
	*p = 0;

	return (p - path);
}

static void parse_inc(const char *include, const char *fname)
{
    bb_key_t *cur;
    const char *p_i;
    llist_t *lo;
    char *ap;
    size_t key_sz;

    if(*include == '/') {
	lo = NULL;
	ap = bb_xstrdup(include);
    } else {
	int w;
	const char *p;

	lo = Iop;
	p = strrchr(fname, '/');    /* fname has absolute pathname */
	w = (p-fname);
	/* find from current directory of source file */
	ap = bb_asprint("%.*s/%s", w, fname, include);
    }

    for(;;) {
	key_sz = bb_qa_simplify_path(ap);
	cur = check_key(Ifound, ap, key_sz);
	if(cur) {
	    cur->checked = cur->value;
	    free(ap);
	    return;
	}
	if(access(ap, F_OK) == 0) {
	    /* found */
	    p_i = ap;
	    break;
	} else if(lo == NULL) {
	    p_i = NULL;
	    break;
	}

	/* find from "-I include" specified directories */
	free(ap);
	/* lo->data has absolute pathname */
	ap = bb_asprint("%s/%s", lo->data, include);
	lo = lo->link;
    }

    cur = xmalloc(sizeof(bb_key_t));
    cur->keyname = ap;
    cur->key_sz = key_sz;
    cur->stored_path = ap;
    cur->value = cur->checked = p_i;
    if(p_i == NULL && noiwarning)
	fprintf(stderr, "%s: Warning: #include \"%s\" not found\n", fname, include);
    cur->next = Ifound;
    Ifound = cur;
}

static size_t max_rec_sz;

static void parse_conf_opt(const char *opt, const char *val, size_t key_sz)
{
	bb_key_t *cur;
	char *k;
	char *p;
	size_t val_sz = 0;

	cur = check_key(key_top, opt, key_sz);
	if(cur != NULL) {
	    /* already present */
	    cur->checked = NULL;        /* store only */
	    if(cur->value == NULL && val == NULL)
		return;
	    if(cur->value != NULL && val != NULL && !strcmp(cur->value, val))
		return;
	    k = cur->keyname;
	    fprintf(stderr, "Warning: redefined %s\n", k);
	} else {
	    size_t recordsz;

	    if(val && *val)
		val_sz = strlen(val) + 1;
	    recordsz = key_sz + val_sz + 1;
	    if(max_rec_sz < recordsz)
		max_rec_sz = recordsz;
	    cur = xmalloc(sizeof(bb_key_t) + recordsz);
	    k = cur->keyname = memcpy(cur + 1, opt, key_sz);
	    cur->keyname[key_sz] = '\0';
	    cur->key_sz = key_sz;
	    cur->checked = NULL;
	    cur->src_have_this_key = NULL;
	    cur->next = key_top;
	    key_top = cur;
	}
	/* save VAL */
	if(val) {
	    if(*val == '\0') {
		cur->value = "";
	    } else {
		cur->value = p = cur->keyname + key_sz + 1;
		memcpy(p, val, val_sz);
	    }
	} else {
	    cur->value = NULL;
	}
	/* trick, save first char KEY for do fast identify id */
	first_chars[(int)*k] = *k;

	cur->stored_path = k = bb_asprint("%s/%s.h", kp, k);
	/* key conversion [A-Z_] -> [a-z/] */
	for(p = k + kp_len + 1; *p; p++) {
	    if(*p >= 'A' && *p <= 'Z')
		    *p = *p - 'A' + 'a';
	    else if(*p == '_' && p[1] > '9')    /* do not change A_1 to A/1 */
		    *p = '/';
	}
}

static void store_keys(void)
{
    bb_key_t *cur;
    char *k;
    struct stat st;
    int cmp_ok;
    ssize_t rw_ret;
    size_t recordsz = max_rec_sz * 2 + 10 * 2 + 16;
    /* buffer for double "#define KEY VAL\n" */
    char *record_buf = xmalloc(recordsz);

    for(cur = key_top; cur; cur = cur->next) {
	if(cur->src_have_this_key) {
	    /* do generate record */
	    k = cur->keyname;
	    if(cur->value == NULL) {
		recordsz = sprintf(record_buf, "#undef %s\n", k);
	    } else {
		const char *val = cur->value;
		if(*val == '\0') {
		    recordsz = sprintf(record_buf, "#define %s\n", k);
		} else {
		    recordsz = sprintf(record_buf, "#define %s %s\n", k, val);
		}
	    }
	    /* size_t -> ssize_t :( */
	    rw_ret = (ssize_t)recordsz;
	    /* check kp/key.h, compare after previous use */
	    cmp_ok = 0;
	    k = cur->stored_path;
	    if(stat(k, &st)) {
		char *p;
		for(p = k + kp_len + 1; *p; p++) {
		    /* Auto-create directories. */
		    if (*p == '/') {
			*p = '\0';
			if (access(k, F_OK) != 0 && mkdir(k, 0755) != 0)
			    bb_error_d("mkdir(%s): %m", k);
			*p = '/';
		    }
		}
	    } else {
		    /* found */
		    if(st.st_size == (off_t)recordsz) {
			char *r_cmp;
			int fd;
			size_t padded = recordsz;

			/* 16-byte padding for read(2) and memcmp(3) */
			padded = (padded+15) & ~15;
			r_cmp = record_buf + padded;
			fd = open(k, O_RDONLY);
			if(fd < 0 || read(fd, r_cmp, recordsz) < rw_ret)
			    bb_error_d("%s: %m", k);
			close(fd);
			cmp_ok = memcmp(record_buf, r_cmp, recordsz) == 0;
		    }
	    }
	    if(!cmp_ok) {
		int fd = open(k, O_WRONLY|O_CREAT|O_TRUNC, 0644);
		if(fd < 0 || write(fd, record_buf, recordsz) < rw_ret)
		    bb_error_d("%s: %m", k);
		close(fd);
	    }
	}
    }
}

static int show_dep(int first, bb_key_t *k, const char *name, const char *f)
{
    bb_key_t *cur;

    for(cur = k; cur; cur = cur->next) {
	if(cur->checked) {
	    if(first >= 0) {
		if(first) {
		    if(f == NULL)
			printf("\n%s:", name);
		    else
			printf("\n%s/%s:", pwd, name);
		    first = 0;
		} else {
		    printf(" \\\n  ");
		}
		printf(" %s", cur->checked);
	    }
	    cur->src_have_this_key = cur->checked;
	    cur->checked = NULL;
	}
    }
    return first;
}

static char *
parse_chd(const char *fe, const char *p, size_t dirlen)
{
    struct stat st;
    char *fp;
    size_t df_sz;
    static char dir_and_entry[4096];
    size_t fe_sz = strlen(fe) + 1;

    df_sz = dirlen + fe_sz + 1;         /* dir/file\0 */
    if(df_sz > sizeof(dir_and_entry))
	bb_error_d("%s: file name too long", fe);
    fp = dir_and_entry;
    /* sprintf(fp, "%s/%s", p, fe); */
    memcpy(fp, p, dirlen);
    fp[dirlen] = '/';
    memcpy(fp + dirlen + 1, fe, fe_sz);

    if(stat(fp, &st)) {
	fprintf(stderr, "Warning: stat(%s): %m\n", fp);
	return NULL;
    }
    if(S_ISREG(st.st_mode)) {
	llist_t *cfl;
	char *e = fp + df_sz - 3;

	if(*e++ != '.' || (*e != 'c' && *e != 'h')) {
	    /* direntry is regular file, but is not *.[ch] */
	    return NULL;
	}
	for(cfl = configs; cfl; cfl = cfl->link) {
	    struct stat *config = (struct stat *)cfl->data;

	    if (st.st_dev == config->st_dev && st.st_ino == config->st_ino) {
		/* skip already parsed configs.h */
		return NULL;
	    }
	}
	/* direntry is *.[ch] regular file and is not configs */
	c_lex_src(fp, st.st_size);
	if(!dontgenerate_dep) {
	    int first;
	    if(*e == 'c') {
		/* *.c -> *.o */
		*e = 'o';
		/* /src_dir/path/file.o to path/file.o */
		fp += replace;
		if(*fp == '/')
		    fp++;
	    } else {
		e = NULL;
	    }
	    first = show_dep(1, Ifound, fp, e);
	    first = show_dep(first, key_top, fp, e);
	    if(first == 0)
		putchar('\n');
	} else {
	    show_dep(-1, key_top, NULL, NULL);
	}
	return NULL;
    } else if(S_ISDIR(st.st_mode)) {
	if (st.st_dev == st_kp.st_dev && st.st_ino == st_kp.st_ino)
	    return NULL;    /* drop scan kp/ directory */
	/* direntry is directory. buff is returned */
	return bb_xstrdup(fp);
    }
    /* hmm, direntry is device! */
    return NULL;
}

/* from libbb but inlined for speed considerations */
static inline llist_t *llist_add_to(llist_t *old_head, char *new_item)
{
	llist_t *new_head;

	new_head = xmalloc(sizeof(llist_t));
	new_head->data = new_item;
	new_head->link = old_head;

	return(new_head);
}

static void scan_dir_find_ch_files(const char *p)
{
    llist_t *dirs;
    llist_t *d_add;
    llist_t *d;
    struct dirent *de;
    DIR *dir;
    size_t dirlen;

    dirs = llist_add_to(NULL, bb_simplify_path(p));
    replace = strlen(dirs->data);
    /* emulate recursion */
    while(dirs) {
	d_add = NULL;
	while(dirs) {
	    dir = opendir(dirs->data);
	    if (dir == NULL)
		fprintf(stderr, "Warning: opendir(%s): %m\n", dirs->data);
	    dirlen = strlen(dirs->data);
	    while ((de = readdir(dir)) != NULL) {
		char *found_dir;

		if (de->d_name[0] == '.')
			continue;
		found_dir = parse_chd(de->d_name, dirs->data, dirlen);
		if(found_dir)
		    d_add = llist_add_to(d_add, found_dir);
	    }
	    closedir(dir);
	    free(dirs->data);
	    d = dirs;
	    dirs = dirs->link;
	    free(d);
	}
	dirs = d_add;
    }
}

static void show_usage(void) __attribute__ ((noreturn));
static void show_usage(void)
{
	bb_error_d("%s\n%s\n", bb_mkdep_terse_options, bb_mkdep_full_options);
}

int main(int argc, char **argv)
{
	char *s;
	int i;
	llist_t *fl;

	{
	    /* for bb_simplify_path, this program has no chdir() */
	    /* libbb-like my xgetcwd() */
	    unsigned path_max = 512;

	    s = xmalloc (path_max);
	    while (getcwd (s, path_max) == NULL) {
		if(errno != ERANGE)
		    bb_error_d("getcwd: %m");
		free(s);
		s = xmalloc(path_max *= 2);
	    }
	    pwd = s;
	}

	while ((i = getopt(argc, argv, "I:c:dk:w")) > 0) {
		switch(i) {
		    case 'I':
			    s = bb_simplify_path(optarg);
			    Iop = llist_add_to(Iop, s);
			    break;
		    case 'c':
			    s = bb_simplify_path(optarg);
			    configs = llist_add_to(configs, s);
			    break;
		    case 'd':
			    dontgenerate_dep = 1;
			    break;
		    case 'k':
			    if(kp)
				bb_error_d("Hmm, why multiple -k?");
			    kp = bb_simplify_path(optarg);
			    break;
		    case 'w':
			    noiwarning = 1;
			    break;
		    default:
			    show_usage();
		}
	}
	/* default kp */
	if(kp == NULL)
	    kp = bb_simplify_path(INCLUDE_CONFIG_PATH);
	/* globals initialize */
	kp_len = strlen(kp);
	if(stat(kp, &st_kp))
	    bb_error_d("stat(%s): %m", kp);
	if(!S_ISDIR(st_kp.st_mode))
	    bb_error_d("%s is not directory", kp);
	/* defaults */
	if(Iop == NULL)
	    Iop = llist_add_to(Iop, bb_simplify_path(LOCAL_INCLUDE_PATH));
	if(configs == NULL) {
	    s = bb_simplify_path(INCLUDE_CONFIG_KEYS_PATH);
	    configs = llist_add_to(configs, s);
	}
	/* for c_lex */
	pagesizem1 = getpagesize() - 1;
	for(i = 0; i < UCHAR_MAX; i++) {
	    if(ISALNUM(i))
		isalnums[i] = i;
	    /* set unparsed chars to speed up the parser */
	    else if(i != CHR && i != STR && i != POUND && i != REM)
		first_chars[i] = ANY;
	}
	first_chars[i] = '-';   /* L_EOF */

	/* parse configs */
	for(fl = configs; fl; fl = fl->link) {
	    struct stat st;

	    if(stat(fl->data, &st))
		bb_error_d("stat(%s): %m", fl->data);
	    c_lex_config(fl->data, st.st_size);
	    free(fl->data);
	    /* trick for fast comparing found files with configs */
	    fl->data = xmalloc(sizeof(struct stat));
	    memcpy(fl->data, &st, sizeof(struct stat));
	}

	/* main loop */
	argv += optind;
	if(*argv) {
	    while(*argv)
		scan_dir_find_ch_files(*argv++);
	} else {
		scan_dir_find_ch_files(".");
	}
	store_keys();
	return 0;
}

/* partial and simplified libbb routine */
static void bb_error_d(const char *s, ...)
{
	va_list p;

	va_start(p, s);
	vfprintf(stderr, s, p);
	va_end(p);
	putc('\n', stderr);
	exit(1);
}

static char *bb_asprint(const char *format, ...)
{
	va_list p;
	int r;
	char *out;

	va_start(p, format);
	r = vasprintf(&out, format, p);
	va_end(p);

	if (r < 0)
		bb_error_d("bb_asprint: %m");
	return out;
}

/* partial libbb routine as is */

static char *bb_simplify_path(const char *path)
{
	char *s, *start, *p;

	if (path[0] == '/')
		start = bb_xstrdup(path);
	else {
		/* is not libbb, but this program has no chdir() */
		start = bb_asprint("%s/%s", pwd, path);
	}
	p = s = start;

	do {
	    if (*p == '/') {
		if (*s == '/') {    /* skip duplicate (or initial) slash */
		    continue;
		} else if (*s == '.') {
		    if (s[1] == '/' || s[1] == 0) { /* remove extra '.' */
			continue;
		    } else if ((s[1] == '.') && (s[2] == '/' || s[2] == 0)) {
			++s;
			if (p > start) {
			    while (*--p != '/');    /* omit previous dir */
			}
			continue;
		    }
		}
	    }
	    *++p = *s;
	} while (*++s);

	if ((p == start) || (*p != '/')) {  /* not a trailing slash */
	    ++p;                            /* so keep last character */
	}
	*p = 0;

	return start;
}